on Continuing Education in Pharmacy.Approved for 0.1 CEU by l’Ordre des
pharmaciens du Québec.
Herbal Products: Determining Quality
by Jane Gillis, B.Sc.(Pharm), Pharm.D
The North American complementary medicine market is experiencing unprecedented growth. Over the past two decades, more people in Canada and the United States have turned to traditional herbal medicines. In 1996, The Globe and Mail reported that 33 percent of Canadians were looking for complementary therapies annually. The data is similar in the United States where it is estimated that between 17 percent and 32 percent of adults have used at least one herb during the previous year.1
The reason for this high level of interest in herbals may be attributed to several consumer attitudes. These include: an increased appreciation for the role that lifestyle choices play in human wellness and disease prevention resulting in a greater interest in achieving a higher level of well-being; the desire to exert greater control over one’s own health care and the willingness to shoulder more responsibility for one’s own health; a dissatisfaction with conventional therapeutic medicine, due mostly to perceived adverse effects of pharmaceuticals; and finally, a sense of frustration and lack of control over the bureaucracy surrounding the current health care system.
Interestingly, consumers are willing to pay the out-of-pocket costs of the various alternative therapies. As the number of consumers wanting to purchase traditional herbal medicines increases, the number of manufacturers willing to sell these products also grows. Annual sales of botanical supplements now exceed $1 billion in both Canada and the United States.2 This has led to a surge in the number of manufacturers bidding for market share. Manufacturers of herbal products vary from large corporate establishments to small independent home-based entrepreneurs. Regardless of size, these companies are aggressively marketing their products. Pharmacies have a relatively small share of the marketplace. It is estimated that of the $1.2 billion annual sales of herbal products in the U.S., only $53 million is sold in pharmacies. The balance is accounted for from sales in health food stores, by naturopathic practitioners, and direct consumer purchases from companies through media and Internet advertising.
Many mainstream health professionals are trying to incorporate complementary therapy into their Western style of medical practice. However, for the most part, both physicians and pharmacists are not recognized as experts in this field. Most North American health care professionals are not trained in traditional herbal medicine. As a result, consumers and patients have been left to make their own decisions about treatment and have sought advice from other sources including friends, family and electronic and printed media. Unfortunately, this has often left the consumer with the perception that pharmacists, physicians and mainstream medical establishments do not condone the use of herbal products. It has even been suggested in consumer publications that pharmacists, physicians and others are hiding the truth about natural products.
It is also recognized that patients frequently do not tell their pharmacist or physician about the herbal preparations they are taking. This may be because they don’t want their decision to be invalidated, or because they simply forget or don’t consider herbs as drug therapy. Ironically, pharmacists are in an ideal position to advise patients on herbal products. With additional training and education on traditional herbal medicines, pharmacists can position themselves as professionally-trained individuals who can assess both prescription, over-the-counter medications and herbal therapies. As pharmacists move towards integrating herbal medicines into their armamentarium of products that they recommend, the profession is faced with many challenges. Pharmacists need education on the benefits and safety of herbal products as well as assurance of quality from manufacturers. This article is a resource to help the pharmacists understand the current issues surrounding the recommendation and sale of herbal products.
USE OF HERBAL PRODUCTS
Most people have experienced the effects of a plant product, whether they realize it or not. People use botanicals in their day-to-day life — everything from coffee or black tea to provide stimulation and help maintain alertness, to peppermint or chamomile herbal teas to help with digestion and upset stomach. Furthermore, approximately 25 percent of “modern” prescription drugs are obtained directly from botanical sources (digoxin, theophylline, morphine, pilocarpine) or derived or patterned synthetically from natural products (acetylsalicylic acid, naloxone, procaine, taxotere).3
Although there is a long history of the use of plant products for health benefits, their use in North America had declined until recently. Now with the current Renaissance, therapies and remedies derived from ancient sources of knowledge, including European, Chinese, East Indian and Aboriginal, are becoming more accepted in contemporary North American societies.
Plants have not only been a historical source of medicine, they have also supplied virtually every ancient culture with food, clothing and shelter. Archeological studies indicate that plants were used for therapeutic purposes prior to any written documentation. One of the first recorded accounts was from the Chinese Herbalist Shen Nung (2800 B.C.) who sought out and investigated the medicinal value of several hundred herbs. He recorded his finding of 365 plant drugs in his Pen Ts’ao. Not only the Chinese, but also the Egyptians, the Greeks and the Romans used herbal remedies extensively in the prevention and treatment of disease. The works of early herbalists/chemists such as Hippocrates, Dioscorides and Galen laid down the basis of what we know today.
|TABLE 1: DRUG|
|Under the Food and Drug Act, a “drug” includes “any substance or mixture of substances manufactured, sold or represented for the use in
The interest in herbal medicines declined with the advent of chemical techniques for isolating various chemical constituents from plants in the 19th century. In 1805, the German pharmacist Serturner extracted morphine from opium, and in the 1820s, two French pharmacists, Joseph Pelletier and Joseph Caventou, isolated several alkaloids from plants including caffeine and quinine. Botanicals began to be viewed as alternative or complementary medicine in North America, separate from what has come to be known as conventional medicine.
In contrast to North America, treatment with herbal medicines in Europe became a well established part of health care. There is a wealth of published German literature to support various phytotherapies. Traditional uses of herbal medicine is an integral part of both physicians’ and pharmacists’ training. In Germany, more than 80 percent of physicians regularly prescribe herbal therapies.4
Over the past 20 years, North America’s interest in “natural” therapies has returned. In response to this, health care professionals started to examine the scientific literature on herbs and are currently conducting many of their own assessments.
CANADIAN REGULATORY STATUS
For several years, there has been an ongoing debate about the regulation of herbal products. The goal is to develop a regulatory framework that will ensure that consumers have freedom of choice and access to products that are safe and of high quality, and that claimed benefits are supported by evidence.5 At present, there is no comprehensive regulatory or policy framework within Health Canada for the regulation of natural health products.
In Canada, herbal preparations are either classified as a drug or a food under the federal Food and Drug Act. (See Tables 1 and 2.) Any herbal product that is offered for sale to diagnose, treat or prevent diseases or symptoms, or any product that makes any health-related claims, is regulated as a drug. As per the Food and Drug Act, in order for a drug to be marketed, it requires a Drug Identification Number (DIN) or a general Product (GP) number. To be granted a DIN for a traditional herbal medicine, an herbal manufacturer must follow Good Manufacturing Practices (GMPs) (see Table 3) and must provide at least two herbal references supporting the intended traditional use of each herbal ingredient. The product must also follow labelling guidelines, which include identification of ingredients (medicinal and non-medicinal), quantity of medicinal ingredients, direction for use, claims and indications and dosage range. The health claims for herbal products classified as drugs are limited to what has been approved by Health Canada.
|TABLE 2: FOOD|
|Under the Food and Drug Act, a “food” is defined as “any article manufactured, sold or represented for use as food or drink for human beings, chewing gum, and any ingredient that may be mixed with food for any purpose whatsoever”|
The alternative classification for herbal preparations is as a food. If an herbal product is deemed to be a food by Health Canada, no health claims are allowed. Also, the manufacturer is not allowed to disclose any recommendations for an appropriate dose. The quality standards for the manufacturing of food is also voluntary and there are no requirements for product review or approval.
REGULATORY PITFALLS AND CONTROVERSY
Natural health products do not adequately fit into the current definition of drug or food as defined in the Food and Drug Act. The Advisory Panel on Natural Products has identified many pitfalls that exist within these regulations as they currently exist. The regulatory controls for drugs have been criticized as being too stringent and cumbersome while the regulatory controls for foods are insufficient.
One deficiency with the current regulatory process is the lack of guarantee of product safety and quality. Many people inappropriately assume that just because herbal products are bottled as a pharmaceutical, there must be standards in place to assure quality. Unfortunately, consumers can not always be guaranteed that a bottle or package contains the product it claims to contain, and that the product was manufactured according to acceptable standards.
For example, several studies measuring the active ingredient in various commercially-available Ginseng products, (ginsenoside) found a great variety among brands.7,8 One group of investigators examined 50 commercial ginseng products sold in 11 countries.8 The products were bought in pharmacies or reputable stores for natural remedies. Each preparation was analysed blind and in triplicate. In 44 of these preparations, the concentration of ginsenosides ranged from 1.9 to 9.0 percent (recommendations suggest at least 7.0 percent ginsenosides). Six products did not contain any specific ginsenosides, of which one preparation contained ephedrine.
GMP are in place to ensure that products made, packaged, imported, or distributed in Canada meet certain basic standards of safety and quality. However, at the present time the Food and Drug Act outlines mandatory GMP only for herbal products classified as drug; voluntary GMPs exist for herbal products classified as a food.
Another insufficiency in the current regulations exists around the health claims that are allowed for the various products. First, products that are regulated as foods are not permitted to make claims of health benefits. This creates a dilemma for consumers, as they are unable to make informed decisions without information on how and when to use the products. Second, Schedule A of the Food and Drug Act lists medical conditions for which treatments, preventatives or cures cannot be sold or advertised to the Canadian public. Therefore, herbal products that are classified as drugs are often not able to make claims that are representative or consistent with the empirical or traditional use of the herb. The purpose of Schedule A is to prevent fraud and to encourage people to seek medical attention for serious conditions. However, this Schedule was enacted in 1934, and may need to be examined and adapted to more modern times.
As with any issue that involves a diverse group of stakeholders, there is controversy over the regulation of herbal products. The debate is essentially centred around the freedom of choice and access for customers versus the need for regulatory intervention to protect public health.
On one side, there are groups requesting that Health Canada put regulations in place that restrict the sale of herbal products to those that are substantiated by evidence from controlled clinical trials. Provincial Pharmacy Regulatory Bodies are receiving increasingly frequent requests, from pharmacists and other health care professionals, for their position on the sale of complementary medicines. As an example, the British Columbia Medical Association (BCMA) recently approved two resolutions at its annual meeting:9
- That the BCMA call upon the B.C. College of Pharmacists to implement measures requiring members of that College to recommend only products shown to be effective in well-designed scientific trials.
- That the BCMA call upon the B.C. College of Pharmacists not to advertise or present unproven therapies to the public as bona fide treatments.
On the other side, many feel that this type of regulation would be too restrictive. If the product is found to meet safety and quality regulations, it is argued that it is unnecessary to also subject them to rigorous clinical trials. Since the evaluation process is lengthy and expensive, there is little opportunity to recover the costs incurred since most products are found in nature and cannot be patented. Also, pharmaceutical testing often requires the isolation and measurement of the effect of a single molecule. This would be complex given the difficulty in isolating the specific active compound in most herbs. Furthermore, increased length of time and cost of production would place vendors at a disadvantage. The vendor would be less competitive in North American markets. As well, since Canadian consumers choices are often influenced by price, they are likely to purchase herbal products imported from the U.S. at a lower cost, even if quality is not assured.
|TABLE 3: GOOD MANUFACTURING PRACTICES (GMP):|
The requirements are prescribed by Division 2, Part C of the Regulations to the Food and Drug Act. Supplementary GMP were developed in October 1996 for the manufacture of Herbal Medicinal Products in order to take into account the unique characteristics of herbal medicines.6
There is no doubt that there is a need to ensure that health claims made are not false or unsubstantiated. Some experts even debate whether claims actually have to appear on herbal products at all. Despite this, many feel that products should be marketed with some claims of the therapeutic effects expected in order for the consumer to make informed decisions about treatment. Others argue that since many products have multiple uses, it is inevitable to exclude some health benefits, thereby resulting in inaccurate information to the public. Also, some health claims have yet to be proven, and the cost of justifying these claims may be prohibitive for some vendors, essentially leading to an inability to market in Canada. Finally, since the current regulations permit herbal products to be sold without label claims, this option should be retained.
RECOMMENDED CHANGES TO CANADIAN REGULATORY STATUS
There is no doubt that the Food and Drug Act must be amended to allow for more appropriate regulation of herbal products. The Health Protection Branch has recognized this need for change and has been trying to address this problem over the last few years. A review process aimed at revising the policy and regulatory framework has been developed. However, after receiving pressure from consumers and the natural health community, Health Minister Allan Rock called a halt to any such changes to the regulations of herbal, nutritional and dietary supplements in October 1997. The Minister asked the Advisory Panel on Natural Health Products to examine and suggest improvements to the policies and regulations governing herbal medicines. These recommendations were presented to the House of Commons Standing Committee on Health in May 1998. The principal objectives of these recommendations were to find a balance between consumers’ freedom of choice and and the need to ensure the availability of safe and quality products. Their recommendations included:
- restructuring the current Food and Drug Act to permit a third category for natural health products.
- developing an effective, transparent and cost-efficient process to license natural health products with a cross section of various experts involved in drafting the new regulations.
- manufacturers, packagers, importers and distributors of natural health products, hold a valid establishment license, which attests to continued compliance to GMPs.
- products meet specific quality and safety tests and provide recognized clinical, traditional or cultural-based evidence to support efficacy.
- products subjected to regulatory review be evaluated to an extent proportional to their potential risks.
- product labels be complete, accurate and informative.
- Schedule A of the Food and Drug Act be abolished .
At the time of writing, no changes to the current regulations have been announced.
Since herbal products are not currently regulated, more pressure is placed on the pharmacist and the pharmacy to recommend herbal products that are safe, supported by evidence and meet manufacturing standards of practice. It is important for pharmacists to educate the public on the proper use of herbal products, and refute any misconceptions they may have about natural health products and their regulation by Health Canada.
WHAT HERBAL PRODUCTS SHOULD I RECOMMEND?
Before looking into the quality of products from various manufacturers, pharmacists must first educate themselves about herbal medicines. This includes information on indications, dosage, dose form, pharmacology, contraindications (including drug-to-drug or drug-to-disease interactions) and possible side-effects. Similar to the wide variety of over-the-counter medications available, pharmacists have to make recommendations from a large array of herbal products. As well, pharmacists will be expected to answer questions and refute or substantiate claims made by various products. Many pharmacists fear this challenge, and have not yet incorporated various herbal preparations into their treatment alternatives. Instead they stock product and let patients make their own decisions on use.
PRODUCT EFFICACY AND SAFETY
The amount of information available on herbal products is endless. As health care professionals trained in evidence-based medicine, pharmacists substantiate efficacy through evaluation of large randomized, double-blind, clinical-controlled trials. Unfortunately, controlled clinical studies do not exist in any quantity for herbal medicines, and due to the costs associated with such studies, it is unlikely that a large number of herbal products will be evaluated by these methods. Therefore, pharmacists must rely on forms and sources of supporting evidence for herbal products that may differ substantially from those required for pharmaceutical evaluation. However, some of the key methods of critically appraising pharmaceutical literature can be applied to information on natural health products.
AUTHOR/ PEER REVIEW
Is the author of the publication recognized in the field? What is his or her background? Has the article or book been peer-reviewed to ensure accurate and appropriate information?
Is the article published in a reputable journal? Does the journal have an editorial board and are the articles peer reviewed? Does the journal focus on providing information or advertising?
Is the article referenced? Is the primary literature referenced? Any claims that are made about herbal product safety or efficacy should refer the reader back to the literature that can substantiate these claims.
How is the journal funded? Is the book or journal published by the manufacturer of herbal products? Not all information from manufacturers is biased, however, books, articles and studies funded by other sources are not likely to have a conflict of interest.
When evaluating actual studies, similar principles always hold true. There is more weight placed on a study that is blinded, where patients are randomly-selected, the treatment is compared to standard therapy or placebo in which the two groups of people have similar characteristics, the sample size is large enough to show effect, the end-points are well-defined, the treatment effect can’t be attributed to confounding factors and the recommendations from the study reflect the sample population characteristics.
Pharmacists must exercise care when taking information at face value. For example, the Internet is generally not a good place to seek information on herbal preparations. Although some sites contain reliable information, most sites have information linked to product promotion and sale. Even after pharmacists become comfortable with the evidence to recommend a number of herbal preparations, they will no doubt be asked questions about other products. Pharmacists should therefore have appropriate herbal references on hand to answer various questions. (See table 4).
More and more monograph’s are becoming available for herbal products. Monographs can contain information on product quality (information, assays and specifications for identity and purity), therapeutic use (information on dosage, dose form, pharmacology, contraindications and side-effects) or both. The following are some examples of pharmacopoeias (or collections of monographs) available to pharmacists:
The United States Pharmacopoeia (USP) has established official standards for the quality of drugs and some vitamins and minerals sold in the United States. Currently, standards for botanicals do not exist, but are being developed. These monographs will contain test methods with specifications involving strength, quality, and purity. The United States Pharmacopoeia Dispensing Information (USP-DI) has published five therapeutic (drug information) herbal monographs: comfrey, feverfew, ginger, hypericum (St. John’s wort) and valerian. The USP-DI is currently preparing to publish more botanical drug information monographs. (http://www.usp.org)
The American Herbal Pharmacopoeia and Therapeutic Compendium (AHP) is currently developing botanical monographs that include a description of each herb’s history, botany, pharmacognosy, chemistry, analytical methods and clinical therapeutics. They hope to produce 300 monographs. (http://www.herbal-ahp.org)
The Commission E is an independent scientific committee set up by the German Federal Health Agency to evaluate herbal remedies. The reference contains over 300 monographs. The monographs are listed as either positive or negative assessments. Positive assessments provide information on indications, dosage, side-effects, drug interactions, contraindications and chemical constituents. Negative assessments provide an explanation as to why there was a perceived lack of benefit with the botanical product. The Commission E was recently translated into English and is published by the American Botanical Council (http://www.herbalgram.org).
The British Herbal Pharmacopoeia (BHP) provides monographs of quality standards for 169 commonly used herbs. The British Herbal Compendium (BHC) is designed as a companion for the BHP and contains therapeutic and regulatory information (http://www.exeter.ac.uk/phytonet/bhma.html).
Pharmacists should also be aware of the evidence supporting the safety of a herbal product. The public often considers all herbal preparations safe because they are natural. This is not always true. Most natural health products have a long history of use and therefore, any potential adverse reaction has been identified. Information on adverse reactions or contraindications can be found in many information sources (see table 4). Such details on adverse effects has been gathered from historical-use documentation, data from in vitro or animal experiments and from clinical observation reports.
HOW CAN I ENSURE PRODUCT QUALITY?
The second biggest challenge facing pharmacists is the need to ensure product quality among the many manufacturers. How can a pharmacist be guaranteed that all manufacturers meet certain standards that confirm a safe and quality product? Unfortunately, current regulations in Canada cannot provide the public or health care professional with that guarantee. To help determine if manufacturing standards are met, the pharmacist must ask the supplier to provide information to support the quality of the product. Here are a few key questions to ask the manufacturer:10
DO YOU FOLLOW GOOD MANUFACTURING PRACTICES (GMP)?
The requirements for GMP are outlined in Table 3.
WHEN WAS THE LAST HEALTH PROTECTION BRANCH AUDIT OF YOUR FACILITY?
This will help ensure that GMP are being followed. Health Canada is currently debating whether to implement Establishment Licenses to be issued annually to show that a manufacturer or distributor meets the appropriate standards. This would result in payment of an establishment licence fee. Mandatory licensing was to come into effect January 1998. However, late in 1997, in response to public pressure, Health Minister Allan Rock announced a halt to this new regulation for natural health remedies. The Advisory Panel on Natural Health Products supported mandatory establishment licensing in its recommendations on the regulatory framework for natural health products.
IS YOUR COMPANY ISO 9000 CERTIFIED?
ISO 9000 is a series of guidelines developed by the International Standards Organization for quality management. The goal of ISO 9000 is to ensure quality assurance at each and every step of the production process. Companies that are registered ISO 9000 have undergone a comprehensive quality assurance audit to verify that all standards have been adhered to in the manufacturing process. To ensure continuous quality improvements, ongoing auditing is carried out on a semi-annual basis. The ISO 9000 Total Quality Management program is not just limited to the pharmaceutical industry, it is available to any manufacturer. Although it is not standard practice for manufacturers of herbal medicines to become ISO 9000 certified, it is another benchmark to measure quality.
DOES YOUR PRODUCT HAVE A DRUG IDENTIFICATION NUMBER (DIN) OR A GENERAL PRODUCT (GP) NUMBER?
As previously outlined, any herbal product that is offered for sale to treat or prevent diseases or symptoms, or makes any health-related claims, is regulated as a drug under the Food and Drug Act and requires a DIN. To be granted a DIN for a traditional herbal medicine, a herbal manufacturer must follow Good Manufacturing Practices (GMP) (see Table 3) and must provide at least two herbal references supporting the intended traditional use of each herbal ingredient. The product must also follow labelling guidelines, which include identification of ingredients (medicinal and non-medicinal), quantity of medicinal ingredients, direction for use, claims and indications and dosage range.
A common misconception by many pharmacists is that only products with DINs are safe and effective. Although a DIN does assure GMP and evidence from traditional sources to back the indication, many herbal products without DINs, that are classified as foods are also safe and effective. Natural health products without DINs should not be overlooked or excluded when making product selection decisions. Instead, pharmacists should ask the manufacturer questions to confirm they follow GMP and that their raw material and finished product has been tested to ensure standards of purity and potency are met.
IS THE RAW MATERIAL TESTED FOR AUTHENTICATION AND IDENTIFICATION OF ACTIVE INGREDIENTS?
|TABLE 4 : HERBAL REFERENCES|
|Tyler VE. Herbs of Choice. Publisher: Pharmaceutical Products Press, Binghamton, NY 1994.Tyler VE. The Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies, 3rd Edition. Publisher: Pharmaceutical Products Press, Binghamton, NY 1993.
Newall CA, Anderson LA, Philipson JD. Herbal Medicines: a guide for the health-care professional. Publisher: The Pharmaceutical Press, London 1996.
Burnham TH. The Lawrence Review of Natural Products. Publisher: Facts and Comparisons, St. Louis, Missouri
Jellin J. Pharmacist’s Letter Continuing Education: Therapeutic Uses of Herbs Volume 1 and 2. Publisher: Therapeutic Research Centre 1998.
Bisset NG. Max Witchtl’s Herbal Drugs and Phytopharmaceuticals. Publisher: Medpharm, Stuttgart, 1994
Schulz V, Hansel R, Tyler VE. Rational Phytotherapy, A Physician’s Guide to Herbal Medicine. Publisher: Springer Verlag, Berlin 1997.
Misidentification of plant material can lead to potential false claims or health risks for the consumer. The primary way to identify plant material is through examination of the features of the entire plant, including flower, leaves and root. However, most herbs arrive at the manufacturer as dried or powdered plant material. They can be identified by various chemical spot testing. The following methods are used to classify compounds: Spectroscopic analysis, such as ultraviolet (UV), infrared (IR), and Fourier-transformer infrared (FTIR), Chromatographic techniques (TLC), high performance TLC (HPTLC), gas chromatography (GC), capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). Plant extracts examined using either spectroscopy or chromatography will display a characteristic profile (fingerprint) which is used in identification.
Another important aspect of testing is evaluating the raw material to rule out adulteration or contamination. Contamination of plant material with bacteria, yeast, fungi, heavy metals, herbicides, pesticides or radio-active substances could potentially lead to adverse reactions.
GMP require that all raw material be identified and classified. Detailed information including geographical source, cultivation and collection techniques, time of harvest, age, nature and extent of fertilization, pesticides, herbicides, insecticides and other contaminants is required. If a manufacturer does not follow GMP, it is important to determine if they employ methods of authenticating and identifying the active ingredients of the raw material. The manufacturer should also have a process in place to ensure raw materials are not contaminated. Finally, always inquire if the manufacturer tests each shipment of raw materials received, versus for example, one in 10 shipments.
HAS THE HERBAL PRODUCT BEEN MANUFACTURED USING STANDARDIZED METHODS?
Due to the inherent nature of plants, there are many factors that contribute to variability in the amount of active ingredient. Even if raw ingredients from two batches of dried plant product have been identified as being similar, variability in their level of active constituents can occur due to environmental factors, temperature, seasonal variations, age of the plant or the plant part harvested.4 During the herbal manufacturing process, a specific concentration is usually extracted. Extraction is simply removing a defined concentration of the herb by mixing the crude herb with an appropriate solvent (alcohol or water). The strength of the extract is often expressed as a concentration. (ie 1:5 or 1:10) The concentration method of expressing the strength of an extract does not accurately measure potency since there may be great variation among manufacturing technique and raw material.11 Standardized extracts help pharmacists guarantee that the herbal product contains a “standardized” or acceptable level of active compounds. Stating the content of active compounds rather than the concentration also helps to provide more accurate dosing.12
Ideally there is a direct relationship between the level of constituents being measured by assay, and the therapeutic activity of the plant. However, many botanical constituents are not well-known or well-defined. In such cases, a marker compound is often identified and chosen for standardized measurements. Unfortunately, the relationship between “marker” compound(s) and the therapeutic effect may be indirect. For example, St. John’s wort preparations are currently standardized to levels of the constituent hypericin (most studies use hypericin 0.3% standardized extract). While hypericin was once thought to be responsible for the antidepressant effects of St. John’s wort, this is now being disputed.13 However, hypericin continues to be used as a quality control marker.
CAN YOU SUPPLY A “CERTIFICATE OF ANALYSIS?”
Manufacturers will have their finished products analysed. The analysis includes tests for the quantitative determination of each active ingredient, the therapeutic activity of constituents or markers, and microbial content.
WHAT METHODS OF STABILITY TESTING DO YOU EMPLOY?
The Certificate of Analysis only verifies that the finished product meets certain standards. It is also important to determine what stability testing is performed to ensure that the product’s potency remains at an appropriate level until the expiry date.
To help ensure safety and quality, have the manufacturer or distributor sign a document verifying that the information provided is correct and accurate. You may also want to request the name of the company’s chief scientist in case you have any questions.
Until effective regulations are in place from Health Canada, pharmacists must be cognizant of all of these issues if they are going to recommend herbal products to their patients. One area of concern for pharmacists is the labelling and advertising of herbal products. Currently, under the Food and Drug Act, the only claims that are allowed for herbal products classified as drugs are the claim(s) that have been approved by Health Canada. Furthermore, the regulation prohibits any health claims about herbal products currently classified as foods. Hopefully, the recommendations of the Advisory Panel on Natural Products are tabled and revisions to the current legislation develops a nice balance between the consumer’s freedom of choice and the safety, effectiveness and quality of product available in Canada.
As time goes on many herbal therapies, once recognized as “alternative”, will take their place among substantiated therapeutic modalities. And indeed, some herbs will be found to be not as effective as initially felt. As the evolution of mainstream herbal therapies occurs, it is absolutely essential that pharmacists remain objective and informed. No doubt we have just begun to learn what secrets rest in Nature’s medicine chest.
Jane Gillis is currently Manager, Professional Services, Unipharm Wholesale Drugs, Richmond, B.C.
1.Jellin JM. Pharmacist’s Letter Continuing Education Booklet: Therapeutic Use of Herbs, Part Two: 1998;98(2):1-43
2.Tyler VE. What Pharmacists should know about herbal remedies. JAPhA 1997;NS 36(10):29-37.
3.Famsworth NR. Medicinal Plants in Therapy. Bulletin of the World Health Organization, 1995.
4.Barrett M. Reference on Evaluating Botanicals. Council for Responsible Nutrition: 1998.
5.Chandler F. Final Report of the Advisory Panel on Natural Health Products – Regulatory Framework for Natural Health Products. May 13, 1998.
6.Michols DM. Good Manufacturing Practice Annexes for Homeopathy Preparations and for Herbal Medicinal Products. October 1996.
7. Consumers Report, November 1995.
8.Cui J, Garle P, Eneroth P et al. What do commercial ginseng preparations contain? Lancet 1994;344:134.
9.Lytle L. Distribution of Alternative and Complementary Health Products. Bulletin – College of Pharmacists of British Columbia 1998; 23(4):1-12.
10.Gillis JE. Quest for Quality. BC Pharmacy 1998;7(2):15-17
11.Murrary MT. Understanding the benefits of standardized botanical extracts. American Journal of Natural Medicine1996;3(80):6-12
12.Bonati A. How and why should we standardize phytopharmaceutical drugs for clinical validation? Ethnopharmacol 1991;32:195-197.
13. Bombardelli E, Morazzoni P. Hypericum perforatum. Fitoterapia 1995;66(1): 43-66.